Vegetables May Provide Breast Cancer Benefit

In a combined analysis of previous studies, higher intake of vegetables was linked with a modestly reduced risk of estrogen receptor (ER)-negative breast cancer. Vegetables did not, however, affect risk of overall breast cancer or risk of ER-positive breast cancer. These results were published in the Journal of the National Cancer Institute.

The relationship between diet and breast cancer has been studied extensively, but few clear links have been identified. The exception to this is alcohol intake, which has consistently been found to increase the risk of breast cancer.

Some studies have found that higher fruit and vegetable intake may modestly reduce the risk of breast cancer, but other studies have found no effect. To explore whether the effect of fruit and vegetable intake varies by the hormone receptor status of the cancer, researchers combined information from 20 previous studies. These studies involved close to one million women (993,466) who were followed for between 11 and 20 years. During follow-up, 19,869 women were diagnosed with ER-positive breast cancer and 4,821 were diagnosed with ER-negative breast cancer.

Fruit and vegetable intake did not affect the risk of overall breast cancer or the risk of ER-positive breast cancer.

Higher vegetable intake was linked with a reduced risk of ER-negative breast cancer. Compared with women with the lowest vegetable intake, women with the highest vegetable intake were 18 percent less likely to develop ER-negative breast cancer.

These results suggest that in addition to their other health benefits, vegetables may help to reduce the risk of ER-negative breast cancer. Although the reduction in risk was not particularly large, the identification of modifiable risk factors for this type of breast cancer is important.